Aqueous solution and methods for manufacture and use

Abstract

Oilfield treatment compositions contain water, hydrochloric acid and urea. The urea and water may be present at a urea/water weight ratio between 0.8 and 12.0, and the hydrochloric acid and urea may be present at a urea/hydrochloric acid molar ratio between 0.1 and 0.5. The compositions are present as one liquid phase. The volumes of the compositions are substantially higher than those of the water volumes; consequently, the amount of water necessary to perform various well-service operations is lower.

1 . A composition, comprising water, hydrochloric acid and urea; wherein:
 (i) the urea and water are present at a urea/water weight ratio between 0.8 and 12.0; and   (ii) the hydrochloric acid and urea are present at a urea/hydrochloric acid molar ratio between 0.1 and 0.5.   
     
     
         2 . The composition of  claim 1 , further comprising a metal-organic framework material. 
     
     
         3 . The composition of  claim 2 , wherein the metal-organic framework material comprises:
 (i) a metal comprising Mg, Al, Ca, Sr, Ba, Sc, Y, Ti, Zr, Hf, V, Nb, Ta, Cr, Mo, W, Mn, Re, Fe, Ro, Os, Co, Rh, Ir, Ni, Pd, Pt, Cu, Ag, Au, Zn, Cd, Hg, Al, Ga, In, Ti, Si, Ge, Sn, Pb, As, Sb or Bi, or combinations thereof; and   (ii) a functional group comprising —CO 2 H, —CS 2 , —NO 2 , —B(OH) 2 , —SO 3 H, —Si(OH) 3 , —Ge(OH) 3 , —Sn(OH) 3 , —Si(SH) 4 , —Ge(SH) 4 , —Sn(SH) 3 , —PO 3 H, —AsO 3 H, —AsO 4 H, —P(SH) 3 , —As(SH) 3 , —CH(RSH) 2 , —C(RSH) 3 , —CH(RNH 2 ) 2 , —(RNH 2 ) 3 , —CH(ROH) 2 , —C(ROH) 3 , —CH(RCN) 2 , or —C(RCN) 3 , or combinations thereof;   wherein R is an alkylene group having 1, 2, 3, 4 or 5 carbon atoms, or an aryl group comprising 1 or 2 aromatic nuclei.   
     
     
         4 . The composition of  claim 1 , further comprising a gelling agent. 
     
     
         5 . The composition of  claim 4 , wherein the gelling agent comprises a viscoelastic surfactant or a water soluble polymer, or both. 
     
     
         6 . The composition of  claim 1 , wherein the composition has a density between 1.22 and 1.45 g/cm 3 . 
     
     
         7 . The composition of  claim 1 , wherein the composition and the water in the composition have volumes, the volume of the composition being between 250% and 1540% larger than the water volume. 
     
     
         8 . A method for preparing a composition, comprising:
 (i) placing water into a container;   (ii) adding urea powder to the water, forming a slurry; and   (iii) introducing hydrochloric acid gas to the slurry until the powder is dissolved and the composition is present as a single phase.   
     
     
         9 . The method of  claim 8 , wherein the composition further comprises a metal-organic framework material. 
     
     
         10 . The method of  claim 9 , wherein the metal-organic framework material comprises:
 (i) a metal comprising Mg, Al, Ca, Sr, Ba, Sc, Y, Ti, Zr, Hf, V, Nb, Ta, Cr, Mo, W, Mn, Re, Fe, Ro, Os, Co, Rh, Ir, Ni, Pd, Pt, Cu, Ag, Au, Zn, Cd, Hg, Al, Ga, In, Ti, Si, Ge, Sn, Pb, As, Sb or Bi, or combinations thereof; and   (ii) a functional group comprising —CO 2 H, —CS 2 , —NO 2 , —B(OH) 2 , —SO 3 H, —Si(OH) 3 , —Ge(OH) 3 , —Sn(OH) 3 , —Si(SH) 4 , —Ge(SH) 4 , —Sn(SH) 3 , —PO 3 H, —AsO 3 H, —AsO 4 H, —P(SH) 3 , —As(SH) 3 , —CH(RSH) 2 , —C(RSH) 3 , —CH(RNH 2 ) 2 , —(RNH 2 ) 3 , —CH(ROH) 2 , —C(ROH) 3 , —CH(RCN) 2 , or —C(RCN) 3 , or combinations thereof;   wherein R is an alkylene group having 1, 2, 3, 4 or 5 carbon atoms, or an aryl group comprising 1 or 2 aromatic nuclei.   
     
     
         11 . The composition of  claim 8 , wherein the composition has a density between 1.22 and 1.45 g/cm 3 . 
     
     
         12 . The composition of  claim 8 , wherein the composition and the water in the composition have volumes, the volume of the composition being between 250% and 1540% larger than the water volume. 
     
     
         13 . A method for treating a formation having a fracturing pressure in a subterranean well having a wellbore, comprising:
 (i) preparing a composition comprising water, hydrochloric acid and urea, wherein the urea and water are present at a urea/water weight ratio between 0.8 and 1.20, and the hydrochloric acid and urea are present at a urea/hydrochloric acid molar ratio between 0.1 and 0.5; and   (ii) placing the composition into the well adjacent to the formation.   
     
     
         14 . The method of  claim 13 , wherein the composition further comprises metal-organic framework material. 
     
     
         15 . The method of  claim 14 , wherein the metal-organic framework material comprises:
 (i) a metal comprising Mg, Al, Ca, Sr, Ba, Sc, Y, Ti, Zr, Hf, V, Nb, Ta, Cr, Mo, W, Mn, Re, Fe, Ro, Os, Co, Rh, Ir, Ni, Pd, Pt, Cu, Ag, Au, Zn, Cd, Hg, Al, Ga, In, Ti, Si, Ge, Sn, Pb, As, Sb or Bi, or combinations thereof; and   (ii) a functional group comprising —CO 2 H, —CS 2 , —NO 2 , —B(OH) 2 , —SO 3 H, —Si(OH) 3 , —Ge(OH) 3 , —Sn(OH) 3 , —Si(SH) 4 , —Ge(SH) 4 , —Sn(SH) 3 , —PO 3 H, —AsO 3 H, —AsO 4 H, —P(SH) 3 , —As(SH) 3 , —CH(RSH) 2 , —C(RSH) 3 , —CH(RNH 2 ) 2 , —(RNH 2 ) 3 , —CH(ROH) 2 , —C(ROH) 3 , —CH(RCN) 2 , or —C(RCN) 3 , or combinations thereof;   wherein R is an alkylene group having 1, 2, 3, 4 or 5 carbon atoms, or an aryl group comprising 1 or 2 aromatic nuclei.   
     
     
         16 . The method of  claim 13 , wherein the composition further comprises a gelling agent, the gelling agent comprising a viscoelastic surfactant or a water soluble polymer or both. 
     
     
         17 . The method of  claim 13 , wherein the composition and the water in the composition have volumes, the volume of the composition being between 250% and 1540% larger than the water volume. 
     
     
         18 . The method of  claim 13 , further comprising allowing the composition to flow out of the formation and the well. 
     
     
         19 . The method of  claim 13 , wherein the composition is placed into the well at a pressure below the fracturing pressure. 
     
     
         20 . The method of  claim 13 , wherein the composition is placed into the well at a pressure above the fracturing pressure. 
     
     
         21 . A method for reducing water volume in a treatment fluid for use in a subterranean well, comprising:
 (i) placing water having a volume into a container;   (ii) adding urea powder to the water, forming a slurry; and   (iii) introducing hydrochloric acid gas to the slurry until the powder is dissolved and a single-phase composition is formed;   wherein, the hydrochloric acid and urea are present at a urea/hydrochloric acid molar ratio between 0.1 and 0.5;   wherein, upon dissolution of the urea, the composition has a volume that is between 250% and 1540% larger than the water volume.